ALL parents will teach their children how to cross a road safely or how to deal with stranger danger.

Yet despite children spending a huge amount of time on the computer, many parents have never discussed how to use the internet safely with them.

Studies suggest that many parents just don't know what their kids are doing online.

Research by Ofcom shows children are putting themselves at risk by posting personal details on social networking sites, yet their parents know little, if anything, about it.

The watchdog found that 27 per cent of eight to 11-year-olds with internet access bypass age restrictions to put their profiles online.

Ofcom warns that many parents and children lack awareness of the issues surrounding privacy and safety on the internet.

It says parents and the companies themselves must do more to monitor children's use of sites like Facebook and Bebo.

Research by the parenting discussion forum Mumsnet found that 41 per cent of parents hadn't even talked about safe internet use with their child and 41 per cent of those who had discussed it said their child wasn't aware of the dangers of talking to strangers in chatrooms.

Another 38 per cent said their child wasn't aware of the danger of giving out personal details on the net.

A government-commissioned review of children's internet safety by the TV psychologist Dr Tanya Byron looked at issues such as cyberbullying, violent games and web predators.

She made a series of recommendations, including the establishment of a UK Council for Child Internet Safety, a clearer ratings system for video games and a public information campaign to educate parents and children in online safety.

Dr Byron also recommends that all computers sold for home use have Kite-marked parental control software and all home internet service providers offer similar free parental control software.

She says: "Young people and children will always want to explore boundaries by taking risks and they will sometimes play this out at home in the digital world, with many parents unaware of this.

"In the same way that we teach our children how to manage real world risk, we need to engage with children as they develop and explore their online and gaming world."

* The Know It All for Parents Guide is available at www.childnet-int.org/kia